A campaigner whose son died after a serious mental illness fears people are dying because a struggling health service "cannot get its act together".
Caroline Aldridge, whose son Tim died in 2014, spoke out about her concerns after a review uncovered unclear and inconsistent mortality data within the Norfolk and Suffolk Foundation Trust (NSFT).
The trust is being accused of "watering down" its data and editing it to remove criticism of its leadership.
During a special Norfolk County Council meeting on September 14, Stuart Richardson, NSFT chief executive officer, said the organisation was working on a plan to improve how data is recorded and apologised for the way the information was recorded.
He admitted the trust "needed help" in terms of its strategy to improve.
According to its own data, 11,379 people who had been cared for as an inpatient or under community services had died while under their care, or within six months of being discharged, in the last five years.
The NSFT has previously pointed out that number would include natural causes, and does not equate to deaths relating to poor care.
But a new report, carried out by accountants Grant Thornton in June this year, stated: "Based on the information made available to us, we are unable to provide assurance over the mortality data reported at the trust.
"The system is unclear and uses multiple systems to record and produce the data. These are a mix of applications, with some manual processes used to categorise and transform the data.
"There is no overarching documentation of the process followed and we saw no clear audit trail of the data as it moved through this process."
Speaking before the Norfolk Health and Overview Scrutiny Committee, Mrs Aldridge said: "Tim died waiting for an appointment and was one of thousands who died in a similar way since.
"I'm in touch with many bereaved relatives. They come along all the time. The deaths seem to be increasing.
"People are dying because they [the trust] cannot get its act together over some basic stuff.
"Everybody knows this is a trust that is struggling. We know it's not good enough but it's as if everybody is just going to turn a blind eye and hope this blows over. But for every family that loses someone, this doesn't blow over. Their pain goes on.
"I've spent nine years asking the same things, offering to be part of the solution, listening to promises and reassurances that it's going to be different. And we always come back to the same place.
"People are going to carry on dying until somebody gets a grip on this."
She was calling on councillors to fight for the people of Norfolk and Suffolk adding it was unclear why people were dying because of "unclear data".
"We need everyone to say enough is enough we are going to make a change now", the campaigner added.
During the meeting, Mr Richardson said the mortality report was damning for the organisation.
He said: "These are people that are loved and lost and we need to know more than the bare facts. We have got to get this fixed. We need help and that [action plan] has to be co-produced.
"This is not a proud moment for us. When we initiated the report to be written. It was done from a point of view that we knew there was a problem that needed to be fixed.
"We've sat here many times talking about NSFT and historical problems and we've worked very hard over the last 18 months to really get to the root cause of what those problems are.
"The way the organisation records data is one of those key problems and is a key pillar to our improvement plan. So getting this report out, having this conversation, as difficult as it is, was very important to us because we have to be open and honest and transparent."
NSFT will work on an improvement plan and the details will be reviewed by Norfolk Health and Overview Scrutiny Committee early next year.
Committee members also backed a motion for the secretary of state to hold a public inquiry into the report.
Another mental health campaigner, Anne Humphrys, also said before the debate: "This isn't about data. This is about people who are forever gone. They don't know how many people have died on their waiting lists or while in their services and so if they don't have accurate data how can they work to prevent people dying in the future.
"I'm hoping NSFT are going to be honest, open and transparent.
"Unfortunately I don't have faith in the organisation having been working with them for coming up to 10 years. There have been no tangible changes and what we see the errors are being repeated year after year and lots of people have tried to make those improvements.
"We often see lots of different chairs and lots of different chief executives who have been replaced and nothing has made that change, so culturally this trust is broken.
"Until some serious work is done to make some changes that will last then we are going to see this keep happening and people will continue to be forever gone."
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know...